The rating is not for actual experience with the device, but in the ease of orientation.- I purchased this device for my sister. I want to have peace of mind at any time of the day & night. Prior to purchase, & especially at night, I couldn't sleep & rest well because I might not be able to hear & detect if there is a problem in her room (which is quite far from my family bedroom). After receiving the device & studying how it works, I also oriented my sister about it, then we familiarized ourselves with the features & did some tests on how it works. It works well especially with its easy to understand directions. Thank you very much. Rose